Protective device



N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20.1916.

Patented Mar. 8, 1921.

3 SHEETSSHEET WITNESSES.-

N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20,1916.

1,370,656. Patentd Mar. 8, 1921 3 SHEETS-SHEET 2.

WITNESSES: M/VE/y 70/? MM W' $400 A TTOR/VE) N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20, 1916.

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Wdneoom W UNITED STATES PATENT OFFICE.

NILS D. LEVIN, OF COL'QMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFACTURINGCOMPANY, OF COLUMBUS, OHIO, A. CORPORATION OF OHIO.

PROTECTIVE DEVICE.

To all whom it may concern: Be it known that I, NJLS D. LEVIN, a citizenof the United States, residing at Columbus, in the county of Franklinand the State of Ohio, have invented certain new and useful Improvementsin Protective Devices, of which the following is a specification,reference being had therein to the accompanyin drawing.

The present invention relates to certain new and useful improvements inprotective devices, and especially in that class of protective devicesby which the auxiliary electrical devices forming part of the circuit ofthe motors of mining machines are protected from accidental ignition ofthe gaseous atmosphere of a coal mine.

Although the greatest precautions are exercised to secure perfectventilation in coal mines, there often occur such accumulations of gasas to render the atmosphere explosive. This is especiall true in theimmediate neighborhood of the working face, where gas often escapes fromthe pockets and crevices of the coal seam in considerable quantities.The very nature of the case requires that the machinery which isemployed for mining the coal should be most commonly used at the pointsmost subject mine.

to gaseous atmosphere. It is, therefore, expedient that the electricmotors by which these machines are actuated, and the accessory deviceswherein electric sparks and flashes frequently occur, should be soinclosed and protected as to prevent the ignition of the gas in theatmosphere of the Sad experience has shown that the best safety devicesare worthless if there is any possibility of their being disregarded byignorant and heedless operators, and any protective device to be a realprotection must be secure against the carelessness and ignorance of thepeople by whom it is used.

It is the especial object of this invention to provide a protectivecasing to inclose the electric fuses, or other circuit interruptingdevices, used in connection with mining machinery, which shall preventthe ignition of the gaseous atmosphere of themine while affordingconvenient access for inspection and adjustment, effectively safeguarding against the ignorance and indifference of the operator of themachine.

The devices by which I attain this object are fully-set'forth in thefollowing specifica- Specification of Letters Patent.

Patented Mar. 8, 1921.

' Application filed October 20, 1916. Serial No. 126,732.

tion and illustrated in the accompanying drawings, but it is to beunderstood that various modifications may be made as to details wlthoutdeparting from the spirit of the invention.

Of the drawings- F igure 1 is a plan view of the preferred embodiment ofmy invention the cover bemg partly broken away to reveal the inter-- nalparts.

Fig. 2 is a section along the line 2-2 of Fig. 1.

Fig. 3 is" an end elevation of the device illustrated in Figs. 1 and 2.

Fig. 4 is a plan view of my improved protective device with the coverclosed and locked.

Fig. 5 is a view similar to Fig. 4 showing the cover unlocked ready tobe opened.

Fig. 6 is a side elevation showing the cover open.

Fig. 7 is an end elevation partly in section showing the application ofremovable plug cable terminals by which the devices within the casingmay be connected with an external circuit.

Figs. 8 and 9 are fragmentary side elevae tion and plan viewsrespectively of the devices shown in Fig. 7.

Like numerals refer to' similar parts in the several figures. 1

Referring to the drawings the numeral 1 indicates, as an entirety, thecast iron casing in which is mounted the apparatus to be protectedagainst accidental ignition of the gaseous atmosphere of a coal mine. For, the purpose of illustration I have shown a fuse cutout which forms apart of the electrical equipment of a mining machine, but it is apparentthat such a casing may be applied 95 to the protection of any electricaldevice subject -to the formation of flashes which might ignite gas. Thiscut out is of the type commonly used with such apparatus and comprises,essentially, two fuse cartridges 2 100 the bottom. 4: of the casing is aslab 5 of 105 slate, or other approved fire and moisture proofinsulating material, which constitutes the base upon which theelectrical parts are mounted. A partition 6, composed of suitableinsulating material, divides the interior 110 of the casinglongitudinally, and separates the fuses of opposite polarity. Secured toductor strips 13 with the terminal binding posts 14 and 15 to which areattached the conductor cables 16 and 17 leading to the motor circuit ofthe mining machine. To the brackets 8 are pivotally connected the switchblades 19, the outer ends of which are adapted to engage the contactblades 20 carried by the brackets 21 in the manner common to knife,blade switches. These brackets 21 are connected through the conductorstrips 22 vei'th the terminal binding posts 23 and 24 to which areconnected the conductor cables 25 and 26 leading from the source ofelectrical supply.

As the binding posts 14, 15, 23 and 24 are alike, a description of oneof them will suffice for all. From the body portion 23 a stem 27 extendsthrough the apertures 28 of the end wall 29 of the casing and to thisstein is screw threaded a nut 30 which serves the double purpose ofholding the binding post in place and of forming'the electricalconnection with the strip 22. In the aperture 28 is snugly fitted aninsulating bushing 31 having a flange engaging the inner face of the endwall 29 of the casing and serving to insulate the connecting strip 22therefrom. Fitted over the projecting end of the bushing 31 is a tube 33formed of some approved insulating material, having an internal flange34 against which the binding post 23 abuts insuch a manner that when thenut 30 is drawn tightly into place the bushing 31 and the tube 33 willbe drawn together to effectually seal the aperture 28, The binding post23 is provided with a transverse aperture 35 into which the end of theconductor cable 25 may be thrust to be clamped tightly in place by theset screw 36. The walls of the casing 1 are extended beyond the end wall29 to form a chamber 37 of suflicient size to contain the binding posts14, 15, 23 and 24 andthe branching cables 16, 17 25 and 26 which connectwith them. This chamber is closed in front by the plate 38' havingapertures 39 through which the cables. pass, and these apertures areprovided with flaring tubes 40 to protect the cables against abrasion.

The casing 1 is provided with a hinged cover 41 having a relativelybroad flange 42 extending entirely around its edge. This flange isadapted to abut against a similar flange 43 formed on the upper edge ofthe casing 1 when in its closed position to form a flame proof joint.Formed on the casing 1 are lugs 44 and 44 towhich the pin 45 is ing.

At the end of the casing 1 opposite to the hinge are upstanding lugs 47and in both these and the hinge lugs 44 and 44 are formed notches 48adapted to engage with flange extensions 49 of the cover toprevent itsrotation about the hinge pin when in the closed position. The lugs 46are so spaced relative to the lugs 44 as to admit of su-f-.

ficient lateral movement of the cover to release the flange extensions.49 from the notches 48, to allow the cover to be turned back to open thecasing.

When the cover 41 is open, the edge 49 of the flange extensions 49engages the hinge lug 44 to prevent lateral movement of the cover 41.Attached to the switch blades 19 are blocks 50 of insulating materialwhich are engaged by the flanges 51 of the crank arms 52. These crankarms 52 are provided with trunnions 53 journaled in apertures 54 of theside plates 55 of the casing, to the outer ends of which are fixed therocker arms 56 by the rotation of which the switch blades 19 may berotated into or out of engagement with the contact blades 20. Theserocker arms 56 are joined together at their outer ends by the cross bar57 to afford a convenient handle for the manipulation of the switch.Both the crank arms 52 and the rocker arms 56 are expanded to form theflanges 58 which engage the faces of the side plate 55 to form flameproof seals for the apertures 54. The shape and proportions of the partsabove described are such that when the switch blades 19 are in theirclosed circuit position the rocker arms 56.- will engage the edges ofthe flanges 42 to prevent lateral movement of the cover therebymaintaining the engagement of the flange extension 48 with the lugs 44,44 and 47 to maintain a flame proof closure of the casing. When,however, the arms 56 have been retated far enough to clear the flange 42and allow the necessary lateral movement of the cover, to release it forrotation about the hinge pin, the switch blades 19 will have been movedfar enough to open the circuit thereby insuring against the accidentalflanges one and a half inches wide will afiord a safe flame proof reliefVent for the pressure of an internal explosion, and afford sufiicientfreedom of motion for the convenient manipulation of the cover plate.

It is often desirable in order to attain flexibility of handling thatthe conductors 16 and 17 shall be removably connected to the deviceswithin the casing. For this purpose I have provided the plug terminals59 and 59' of the well known, construction. As shown in, Fig. 7, theplug 59 consistsof a metallic terminal 60 soldered to the conductor '61and incased' in an insulating sleeve 62. In this terminal 60 is formed asocket 63 adapted to engage with the upstanding stud 64 positioned inalinement with a suitable aperture 65 in the wall 66 of the casing 1.The stud 64 is supported by an insulator 67 fixed to a flange 68 of thecasing 1 and is connected with the binding post 14 throu h the conductorstrip 69.

Formed on the plug 59-is a flange 70 adapted to be engaged by theextension 71, formed on the flange 42, when the cover 41 is in closedposition. The proportions of the flange extension 71 are such that whenthe cover 41 is moved laterally to its unlocked position the flanges 70will be disengaged, permitting the withdrawal of the plugs to disconnectthe cables 16 and 17. By this arrangement the plugs 59 and 59 are lockedagainst removal at all. times when current is flowing through the cables16 and 17 and the first step looking toward their withdrawal opens thecircuit, thus insuring against the formation of arcs between the socket63 and studs 64.

What I claim is 1. In a device of the class described, the combinationof a casing, a hinge upon the casing,a cover both rotatable and slidableupon the hinge, a circuit breaker within the casing, and means madeeffective by sliding movement of the cover to prevent the opening ofsaid cover while the circuit breaker is closed or the closing of thecircuit breaker while the cover is open.

2. In a deviceof the classdescribed, the

combination of a casing, a hinge upon the casing, a cover both rotatableand slidable upon the hinge, means to lock the cover in closed position,a circuit breaker within the casing, and means made effective by slidingmovement of the cover to prevent the unlocking of the cover while thecircuit breaker is closed or the closing of the circuit breakerfi whilethe cover is unlocked.

3. In a device of the class described, the

combination of a casing, a hinge upon the casing, a cover both rotatableand slidable upon the hinge, means made eflective by sliding movement ofthe cover to lock said cover in closed position, a circuit breakerwithin the casing, a lever outside the cas-' ing to control the circuitbreaker, said lever being so disposed as to prevent "unlocking the coverwhile the circuit breaker is closed or closing the circuit breaker whilethe cover is unlocked.

4. In a device of the class described, the combination of a casing,-acover hinged to the casing, devices on the casing to engage the coverwhen in closed position to prevent rotation upon the hinge andreleasable by lateral movement of the cover, a circuit breaker withinthe casing, a lever outside the casing to control the circuit breaker,said lever being so disposed as to prevent lateral movement of the coverwhile the circuit breaker is closed and to prevent reclos-v ing thecircuit breaker before returning the cover to the closed position.

5. In a device of the class described, thecombination of a casing, ahinge upon the casing, a cover both rotatable and slidable upon thehinge, removable means to connect the devices within the casing to anexternal circuit, and means made effective by sliding movement of thecover to prevent the removal of the connecting means.

6. In a device of the class described, the combination of a casing, ahinge upon the casing, a cover both rotatable and slidable upon thehinge, removable plug terminals adapted to connect the devices withinthe casing with an external circuit, and means made efiective by slidingmovement of the cover to prevent the withdrawal of the plugs while thecover is closed.

7. 'In a device of the class described, the combination of a casing,ahinge upon the casing, a cover both rotatable and slidable upon thehinge, a circuit breaker within the casing, removable plug terminalsadapted to connect the devices within the casing with an externalcircuit, and means made effective by sliding movement of the cover torevent the withdrawal of the plugs whide the circuit breaker is closed.

8. In a device of the class described, the combination of a casing, acover hinged to. the casing and adapted to limited lateral movement,devices on the casing adapted to engage the cover when in closedposition to lock it against rotation upon the hinge, acircuit breakerwithin the casing, a ,lever outside the casing to control the circuitbreaker, said lever being so disposed as to prevent lateral movement ofthe cover to release. the locking devices while the circuit breaker isclosed, plug terminals adaptedto connect the devices within the casingwith an external circuit and'flanges, on the plugs engageable by thecover when in closed position to prevent removal of the plug.

9. In a device of the class described, the combination of a casing, acover 'for the casing, a circuit breaker within=the casing,

means made effective by lateral movement of the cover to prevent theopening of the cover while the circuit breaker is closed, and to preventclosing the circuit breaker while the cover is opened.

10. In a device of the class described, the combination of a casing, alaterally movable cover for the casing, a circuit breaker within thecasing, a lever outside the casing to control the circuit breaker, saidlever being so disposed as to prevent movement of the cover while thecircuit breaker is closed, and means to prevent reclosing the circuitbreaker while the cover is opened.

11. In a device of the class described, the

combination of a casing, a laterally movable cover for the casing, a crcuit breaker, w1th1n the casing, means outside the casing to actuatethe circuit breaker and adapted to prevent movement of the cover whilethe circuit breaker is closed and to prevent closing the circuit breakerwhile the cover is open. 7

12. In a device of the class described, the combination of a casing, alaterally movable cover for the casing, a circuit breaker within thecasing, a lever outside the casing to control the circuit breaker, saidlever being so disposed as to prevent lateral movement of the coverwhile thecircuit breaker 4 combination of a casing havingcontact devicestherein, removable plug terminals adapted to connect said devices,respectively, with .an external circuit, and a cover for. the casinghaving a flange movable therewith independently of said connecting meansand adapted to engage with said means and prevent their removal when thecover, is in closed position. a

15. In a device of the class described, the combination of the casinghaving contact devices therein, removable plugterminals adapted toconnect said devices, respectively, with an external circuit, and acover for the casing movable'laterally relatively thereto and adapted,when moving. laterally, to engage with said terminal'lugsand preventtheir removal when the cover is in closed position 16. In a device oithe class described, the combination of a casing, a cover for the casingadapted to limitedlateralmovement, devices on the casing adapted toengage the cover to lock it in closed position, a circuit breaker withinthe casing means outside the casing to control the circuit breaker, saidmeans being adapted to prevent the unlocking of the cover while thecircuit breaker is closed and to prevent reclosing the circuit while thecover is unlocked.

17. In a device of the class described, the

combination of a casing, a cover for the casing adapted to limitedlateral movement, devices on the casing adapted to engage the cover tolock it in closed position, a circuit breaker within the casing meansoutside the casing to control the circuit breaker, said means beingadapted to prevent unlocking the cover while the circuit breaker isclosed and to prevent reclosing the circuit breaker while the cover isunlocked, removable plug terminals adapted to connect the devices withinthe casing with an external circuit,. and means to prevent the removalof the plugs While the cover is closed.

18. In a device of the class described, the combination of a casing, acover hinged to thecasing and adapted to limited lateral movement, acircuit breaker within the casing, removable means to connect thedevices within the casing with an external circuit and means madeeffective by the lateral movement of the cover to prevent the removal ofthe connecting means while the circuit breaker is closed.

' 19. In a device of the class described, the combination of a casing, acover hinged to thecasing and adapted to limited lateral movement, acircuit breaker within the casing, removable plug terminals adapted toconnect the devices within the casing to an external circuit, and meansmade effective by the lateral movement of the cover to prevent theremoval of the plugs while the circuit breaker is closed.

20. In a device of the class described, the combination with a casing ofa cover hinged to the casing and adapted to limited lateral movement,devices on the casing adapted to engage the'cover when in closedposition to lock it against rotation upon the hinge, removable plugterminals adapted to connect the devices within the casing with anexternal circuit, and means made effective by the lateral movement ofthe cover to prevent the withdrawal of the plugs while the cover islocked.

21. In a device of the class described, the combination of a casing, alaterally movable cover for the casing, a circuit breaker cover whilethe circuit breaker is closed or one direction to close the casing andin a direction angular thereto to lock the cover closed, a circuitbreaker within the casing, and means to prevent unlocking the coverwhile the circuit breaker is closedor closing the circuit breaker whilethe cover is unlocked.

23'. In a device of the class described, the

combination of a casing, a cover movable in locking the cover while thecircuit breaker 15 is closed or closing the circuit breaker while thecover is unlocked.

In testimony whereof I afiix my signature, in the presence of twowitnesses.

NILS' D. LEVIN.

Witnesses: K

DUDLEY T. FISHER, HARRYO. DEAN.

